A few airhead questions

[QTreiber]

I am the happy owner of a 1978 R100/7. The bike runs great and I am trying to get to know it better.

A few questions:

- Is it normal that the throttle grip does not go fully back from full throttle to its original position?

- Is it normal that the center stand does not go up completely by itself? I always have to lift it up with my foot. Would new springs or bushings help?

- Compared to my 2005 R1200 GS the bike feels less stable and "precise" around corners. Do I just have to live with it or what can be done to improve stability?
The bike has almost new Dunlop D404 tires.
The bike has Koni shocks. Would new shocks potentially improve stability?

- The bike has "JAMA Engineering" mufflers. I like the deep, but not overly loud sound. Are these aftermarket mufflers?

- I am afraid I know the answer for this one...Is there a source to get a copy of the owners manual either as hardcopy or electronically?

Thank you in advance and greetings from Colorado,
Armin

 

[20774]

- Is it normal that the throttle grip does not go fully back from full throttle to its original position?

Check the small friction screw on the underside of the throttle. You could have too much drag on it...it's not really meant to be a cruise control but to help control the throttle during tune ups, etc. Also, you might need to take the assembly apart and lube the tube.

- Is it normal that the center stand does not go up completely by itself? I always have to lift it up with my foot. Would new springs or bushings help?

Can't remember...I've had a Reynolds rideoff for a long time. Seems to me you do have to assist it up. But a thorough servicing might be in order. Lube the bushings and definitely check the spring tension.

- Compared to my 2005 R1200 GS the bike feels less stable and "precise" around corners. Do I just have to live with it or what can be done to improve stability?
The bike has almost new Dunlop D404 tires.
The bike has Koni shocks. Would new shocks potentially improve stability?

Might just be the nature of the beast. But new shocks, overhauling the front forks, getting the right air pressures, making sure the swingarm bearings are properly setup could also contribute.

- The bike has "JAMA Engineering" mufflers. I like the deep, but not overly loud sound. Are these aftermarket mufflers?

Yes.

- I am afraid I know the answer for this one...Is there a source to get a copy of the owners manual either as hardcopy or electronically?

Several places sell owner's manuals. Capital Cycle, Motobins...I believe Bob's BMW probably does. Also check with your dealer...they should be able to get one also.

Enjoy the bike...I do mine.

 

[Yarddog]

* THROTTLE: Probably not normal...suggest a cleaning of all related parts and proper lubing, but a lotta of us old Harley pilots don't consider that a problem! The old Harleys, before the government decided that it was better qualified to make decisions that we used to make just fine on our own, didn't have a throttle return spring, and you physically closed the throttle yer own self...I removed as many throttle springs on my S&S to get it back to this point, but there's still a light spring workin' somewhere...on my Beemer, I replaced the original stiffer than you know what springs with much lighter springs, and if I coulda gotten away with it, I would have removed them altogether, but my '78 doesn't have double throttle cables, and the one cable is too limp to handle both directions... But just in the interest of keeping things well maintained, I'd take it all apart and do the cleaning and lubing deed...

* CENTERSTAND: Again, clean everything up and lube it up...however, you may have to replace the springs, OR shorten them a bit...It looks to me like things in that area get a little warmish, and heat can be the enemy of spring temper. Just put this down on your to-do list, and after you get done, it will probably work just fine!

* HANDLING: That's why they call it 'progress'!! I'm no expert in the field of BMW handling, but I rather suspect that you'll play hob ever trying to get your older bike to handle like your new bike...Obviously, you can go thru the bike, do all the required maintenance, make sure your front and rear suspension are working at the optimal level...but at the end of the day, you have a thirty some odd year old bike, and comparing it to a new design is like...well...apples and oranges!!!

* THE OTHER TWO QUESTIONS: I will leave to somebody else, but I, too, would like to have a fresh copy of the owner's manual...I bought an old, mildewed one off of eBay, but...well...

 

[moose738]

-Is it normal that the throttle grip does not go fully back from full throttle to its original position?
No, this is not normal. It sounds like you will need to disassemble the throttle assembly, clean up the gears, and apply some new grease.

- Is it normal that the center stand does not go up completely by itself? I always have to lift it up with my foot. Would new springs or bushings help?
Yes, this is normal. The stock center stand will not retract to the 'stored' position. It needs to be pushed up as you have been doing.

- Compared to my 2005 R1200 GS the bike feels less stable and "precise" around corners. Do I just have to live with it or what can be done to improve stability?
The bike has almost new Dunlop D404 tires.
The bike has Koni shocks. Would new shocks potentially improve stability?
Asking a 1978 bike to handle like a 2005 bike might be asking too much.

- The bike has "JAMA Engineering" mufflers. I like the deep, but not overly loud sound. Are these aftermarket mufflers?
I'm am not familiar with JAMA mufflers, but am sure there would be aftermarket.

- I am afraid I know the answer for this one...Is there a source to get a copy of the owners manual either as hardcopy or electronically?
ebay

Good luck....John

 

[AnnapolisAirhead]

- Is it normal that the throttle grip does not go fully back from full throttle to its original position?

No, not normal. There can be several factors contributing this problem (I chased it on mine too). The throttle tension screw on the forward underbelly of the throttle may be tight as Kurt mentioned. On '81 and newer bikes, there is a single cable to the throttle and a splitter on top of the engine top--yours being a '78 I *think* has both cables terminating at the throttle. If not, you may need to adjust the barrel nut at the splitter. Each carb also has a throttle return spring that could be worn out--I replaced my springs with http://tinyurl.com/Bing-40mm-carb-springs

Your cables housings could also be worn and/or the cable oxidized, so a replacement set wouldn't hurt.

...The bike has Koni shocks. Would new shocks potentially improve stability?

Without question, in my opinion as well as the changes others have recommended. those may be the originals not sure.

It won't ever handle like your newer bike--even if both were new (they were both built for different purposes, to boot) but there is a sweetness to any old Airhead with a properly tuned suspension. I think you also have the heavy flywheel which has a cadence that is just a very cool feel. 1981 and newer had lighten flywheels, not the same.

- The bike has "JAMA Engineering" mufflers. I like the deep, but not overly loud sound. Are these aftermarket mufflers?

Definitely and good ones. They come in stainless and chrome, both with a new yet not obnoxious sound. If yours have a slight yellow/gold tinge to them, they are the stainless ones. I have a set of chromed one what are in great shape 12 years later.

 

[radar41]

Airhead local help

I am the happy owner of a 1978 R100/7. The bike runs great and I am trying to get to know it better.

- I am afraid I know the answer for this one...Is there a source to get a copy of the owners manual either as hardcopy or electronically?

Thank you in advance and greetings from Colorado,
Armin

Armin,

I'm just northwest of you in Longmont.

There are several of us "airheads" in the area who can be of some assistance should you need local advice/help, etc. My RS is currently undergoing a update for painting and some minor mechanical stuff, so I have local painters, powdercoaters and sources for airhead parts should you need them.